What is it better ?

Question

Hi All,
I would like to know your option...
What is the better approach between (a) and (b) ?
a)
MyClass t = null;
for (int i;......) {
    t = new MyClass();
}b)
for (int i;......) {
    MyClass t = new MyClass();
}Cheers,
ste

Answer 1

What about memory usage or garbage collector ?
hardly a difference, if any.
In my opinion B (or c) is better from the garbage
collector point of view, not sure about memory
usage.it isn't. At most, and only if we're talking about a method that runs beyond the next garbage collection cycle, a single instance might take one garbage collection cycle longer to become eligable for garbage collection and be collected in the first scenario.
Unless you're talking about objects taking massive amounts of memory per instance that's peanuts.
Of course, the most expensive operation is new
MyClass(), but in B the jvm should create any time a
new variable (i mean a new pointer container); in A
just the same pointer changes value (pointing to the
new object)
If you're so worried about those few theoretical microseconds you might save why not declare every variable as a member of the class so you won't have to declare them every time you pass through that method?
Not saying you should (good design practice says you shouldn't) but given your reasoning that would be the logical choice.
But you can't say what'll happen exactly. The compiler or JVM might well decide to optimise away that declaration.